Dimension and crushed stones
The group of mineral raw minerals, assigned in this Report to the Dimension and Crushed Stones comprises 33 lithological varieties of igneous, sedimentary and metamorphic rocks displaying properties which make them useful in domestic economy. The stones are used to produce crushed aggregates – a high-grade raw material for building and road and railway construction and stone elements for Road construction (stone for paving roads, stone and stone plates for sidewalks, stone street curbing and curb ramps) and building construction (stone blocks, decorative plates for elevation and facade, floor plates and slabs).
Sedimentary rocks represent about 47 % of proven resources of dimension and crushed stones and igneous rocks - 44 % of the resources. The share of metamorphic rocks is much smaller, not exceeding 9 % of the resources.
Igneous and metamorphic rocks explored as dimension and crushed stones occur mainly in the Lower Silesian region where they are represented by basalts, granites, gabbros, syenites, melaphyres, porphyres, amphibolites, gneisses, migmatites, serpentinites and marbles) and form a few deposits in the Małopolska voivodeship (diabases, melaphyres, porphyres and porphyric tuffs). Sedimentary rocks matching requirements for that use are much more common. Limestones and dolomites form numerous deposits in the Holy Cross Mts and the Silesian-Cracow region and sandstone deposits were proven in the Carpathian region and Holy Cross Mts and Lower Silesia. In turn, deposits of limestones, opokas and marls were proven in the Lublin Upland.
Location of dimension and crushed stones deposits is presented on two separeted maps - for South-Western Poland and for South-Eastern Poland.
According to: Regulation of the Minister of the Environment (which were obligatory between 1.01.2002 and 31.12.2011) and the limit values of the parameters that defines the deposit (obligatory since 1.01.2012) dimension and crushed stones are documented to the depth of opencast exploitation system. For dimension stones the most important is geological divisibility stated for any type of rock: 5 % of volume for marls and serpentinites, 10 % for syenite, gabbro, granodiorite, 20 % for granite, tuff, sandstone. For crushed stones average compression strength should be more than 80 MPa and abradability in Los Angeles drum should be maximum 35 %.
Deposits of mineral raw materials for road and building construction are explored down to the depth to which their exploitation is technically and economically justified exploitation.
Table 1 shows the current state of exploration and development of the dimension and crushed stones.
Anticipated economic resources, documented within 731 deposits, amounted to 10,424.97 million tonnes in 2011 – 251.18 million tonnes bigger than in 2010. There were 26 new deposits documented in 2011 and 2 deposits crossed out of the “Balance…”.
Resources of exploited deposits states for 49 % (5,223.86 million tonnes) of total anticipated economic resources and are documented within 315 deposits.
Economic resources amounted to 3,372.25 million tonnes in 2011 and increased by 190.68 million tonnes in comparison with 2010.
According to data provided by operators of exploited deposits, production of dimension and crushed stones in 2011 raised to 84.58 million tonnes and was 21.35 million tonnes higher than in the previous year. The increase was the highest in the case limestone production (by 71 %), granites (38 %), basalt (35 %), dolomites (27 %), melaphyre (26 %) and sandstone (20 %). The production is concentrated within the area of two voivodeships: dolnośląskie and świętokrzyskie with the share in Polish output of dimension and crushed stones of 42 % and 34 % respectively.
Dimenshion and crushed stones are exploited also during brown coal exploitation from non-documented deposits. In 2011 there were 5.06 thousand tonnes of erratic boulder, 193.01 thousand tonnes of limestone and 4.71 thousand tonnes of sandstone exctracted from Bełchatów and Szczerców fields (KWB Bełchatów SA mine). The output of KWB Adamów SA mine amounted to 1.27 thousand tonnes of erratic boulder.
The figure given below shows changes in domestic resources and production of dimension and crushed stones in Poland in the years 1989-2011.
Table 2 shows the current state of exploration and development and production with breakdown of individual lithological types of rocks used in road and building construction.
Prepared by: Elżbieta Tołkanowicz, Krzysztof Żukowski
Table 1. Dimension and crushed stones - million tonnes